react-dates version
e.g. react-dates@21.8.0

Describe the bug
Minor issue in that the right border is not visible. I was able to override this class to fix it, so not an urgent bug for me. I can submit a PR at some point if no one gets to this.

Source code (including props configuration)
Steps to reproduce the behavior:

<DateRangePicker
  startDate={this.state.startDate}
  startDateId="your_unique_start_date_id"
  endDate={this.state.endDate}
  endDateId="your_unique_end_date_id"
  onDatesChange={({ startDate, endDate }) => this.setState({ startDate, endDate })}
  focusedInput={this.state.focusedInput}
  onFocusChange={focusedInput => this.setState({ focusedInput })}
/>

Screenshots/Gifs

Desktop (please complete the following information):

• OS: macOS 10.14.6
• Browser: Chrome
• Version: 80.0.3987.132

Fix
Would just need to update the block below to add box-sizing: border-box:
https://github.com/airbnb/react-dates/blob/480b9902d69e64e62a2ef5c2d3b5fc3adef94444/src/components/DateInput.jsx#L306-L324